* The volume creation time (part of the volume information) of the volume the Prefetch file was created on.

* The volume creation time (part of the volume information) of the volume the Prefetch file was created on.

−

The creation date of the Prefetch file indicates the first time the application was executed. Both the modification date of the Prefetch file and the embedded Last Run timestamp indicate the last time the application was executed.

+

The file system creation time of the Prefetch file indicates the first time the application was executed. Both the file system modification time of the Prefetch file and the embedded last run time indicate the last time the application was executed.

== Prefetch hash ==

== Prefetch hash ==

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* [http://www.invoke-ir.com/2013/09/whats-new-in-prefetch-for-windows-8.html What's New in the Prefetch for Windows 8??], by Jared Atkinson, September 21, 2013

* [http://www.invoke-ir.com/2013/09/whats-new-in-prefetch-for-windows-8.html What's New in the Prefetch for Windows 8??], by Jared Atkinson, September 21, 2013

Revision as of 14:49, 13 March 2014

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Windows Prefetch files, introduced in Windows XP, are designed to speed up the application startup process. Prefetch files contain the name of the executable, a Unicode list of DLLs used by that executable, a count of how many times the executable has been run, and a timestamp indicating the last time the program was run. Although Prefetch is present in Windows 2003, by default it is only enabled for boot prefetching. The feature is also found in Windows Vista, where it has been augmented with SuperFetch, ReadyBoot, and ReadyBoost. For SSD drives Prefetch is disabled by default [1].

Up to 128 Prefetch files are stored in the %SystemRoot%\Prefetch directory [2]. Each file in that directory should contain the name of the application, a dash, and then an eight character hash of the location from which that application was run, and a .pf extension. The filenames should be all uppercase except for the extension. The format of hashes is not known. A sample filename for md5deep would look like: MD5DEEP.EXE-4F89AB0C.pf. If an application is run from two different locations on the drive (i.e. the user runs C:\md5deep.exe and then C:\Apps\Hashing\md5deep.exe), there will be two different prefetch files in the Prefetch folder.

The size of the Prefetch file (sometimes referred to as end of file (EOF)).

The files and directories that were used doing the application's start-up.

Timestamps

The Prefetch file contains 2 types of timestamps

The time when the application was last ran (executed). Version 26 of the Prefetch format maintains 7 previous last run times.

The volume creation time (part of the volume information) of the volume the Prefetch file was created on.

The file system creation time of the Prefetch file indicates the first time the application was executed. Both the file system modification time of the Prefetch file and the embedded last run time indicate the last time the application was executed.

Prefetch hash

There are multiple known hashing functions to be used for prefetch file filename hashing, namely: